Structure and Properties of Cationic Poly(vinyl alcohol)

Abstract

In this study, through the macromolecule reaction, poly(vinyl alcohol) (PVA) was modified by quaternary ammonium cationic monomer (QAC) and the cationic PVA (C-PVA) was synthesized successfully. The structure of C-PVA was characterized by Fourier-transform infrared and Kjeldahl nitrogen content measurement. The properties of PVA were studied in terms of surface property, mechanical property, crystallization, and dynamic mechanical property. The results indicated that introduction of cationic groups onto the molecules of PVA resulted in an increase in hydrophilicity of PVA. The crystallization property was enhanced and the glass transition temperature decreased with increasing dosage of QAC due to the weakening of the intramolecular and intermolecular hydrogen bonding of PVA. The stress—strain curves of C-PVA showed a ductile fracture, and the elongation at break of C-PVA can be improved from 62.95% for pure PVA to 461.5% without much decrease in the tensile strength.